A probe device is used to test the electrical properties of a chip formed on a wafer.
FIG. 1 is a diagram showing a general probe card 10. Referring to FIG. 1, the probe card 10 includes a substrate (ceramic, glass, wafer, or the like) 11, an electrode 12 formed on the substrate, and a plurality of probes 13 bonded to the electrode.
A chip on a wafer fabricated via semiconductor fabrication receives an electrical signal through pads formed on the chip to perform a predetermined operation and, then, re-transmits a processing result to a wafer test system through the pads and, in this case, a probe card is used to determine whether the chip is appropriately operated.
FIG. 2 is a diagram showing a conventional probe bonding device 20.
Referring to FIG. 2, the conventional probe bonding device 20 includes a tray 21, a first gripper 22, a forming unit 23, a second gripper 24, a solder bath 25, a chuck unit 26, a vision device 27, and a laser unit 28.
The conventional probe bonding device 20 is configured in such a way that a probe installed on the tray 21 is gripped by the first gripper 22, is moved to the forming unit 23 and, then, is mechanically aligned using the forming unit 23. Then, the probe is gripped by the second gripper 24 and is dipped into the solder bath 25 to coat a lower portion of the probe with a solder paste. Then, the second gripper 24 moves the probe with the solder paste coated thereon to a bonding position of a substrate fixed onto the chuck unit 26 and the laser unit 28 irradiates a laser beam to the probe to complete bonding. To enhance the quality of a probe card, the precision of a bonding position of a probe is very important and, to this end, the conventional probe bonding device 20 adjusts the probe to be bonded to a precise bonding position using the vision device 27.
A camera included in the vision device 27 performs photographing vertically downward and toward the substrate fixed onto the chuck unit 26 from above the chuck unit 26 and, in this regard, there is no problem in terms of control of horizontal coordinates (x and y coordinates) of a bonding position of the probe but there is a problem in that it is not possible to accurately measure a height (z coordinates) to the probe from the bonding position.
In general, the probe is positioned above the horizontal coordinates of the bonding position using the second gripper 24 and, then, is lowered to contact the bonding position. In this case, when a height to the probe from the bonding position is not accurate, even if the probe contacts the bonding position, the probe is forcibly lowered or even if the probe does not contact the bonding position, a laser irradiation process is terminated and, accordingly, problems arise in that a minute error arises in a position of the probe or the bonding quality of the probe is degraded.